Protector means for looms



June 20, 1967 G. T. GURNEY PROTECTOR MEANS FOR LOOMS Filed Sept. 29, 1965 United States Patent 3,326,246 PROTECTOR MEANS FOR LOOMS Gordon T. Gurney, Worcester, Mass assignor to Crampton 8: Knowles Corporation, Worcester, Mass, a corporation of Massachusetts Filed Sept. 29, 1965, Ser. No. 491,459 8 Claims. (Cl. 139341) This invention relates to protector means for looms operating in such manner as to give indication of timely or untimely arrival of a shuttle at a shuttle box without, however, retarding the shuttle by the method of indication.

A method of indicating protection of a loom which has gone into general use in recent years, shown in US. Patent No. 2,781,794, includes a permanent magnet embedded in the lay between shuttle boxes on the lay and having at least one of its poles surrounded by a wire coil over which a magnetic body on a shuttle passes to generate an electric impulse which can be used to permit the loorn to continue running if the shuttle is on time or stop the loom if the shuttle is late.

When a shuttle having considerable ferrous metal in its makeup is used it is found that the magnet is likely to retard the shuttle so that the latter, even though arriving at the magnet and coil on time and therefore giving promise that it will arrive at the shuttle box on time, nevertheless will be retarded sufiiciently by the drag of the permanent magnet to cause it to arrive late.

It is the general object of the present invention to provide an electric protection means operating somewhat on the same general principle as that shown in the aforesaid patent, but with the improvement that no permanent magnet is necessary and therefore the shuttle is not subject to any appreciable retarding force which might slow it down after it has given indication of timely arrival at the shuttle box toward which it has been picked. The shuttle may contain considerable ferrous metal but the present invention, not requiring a magnet for its operation, can give indication without the risk of slowing the shuttle down.

It is a further object of the invention to provide a protection system of the general type mentioned which can operate with a shuttle made of a light metal such as aluminum or magnesium or any other light metal which is not magnetic but which is capable of conducting electricity.

In some shuttles the delivery eye for the Weft is made of bronze which is unsuitable for the magnetic protection previously mentioned, but would be suitable for a protection made according to the present invention.

With these and other objects the invention resides in the combination and arrangement of parts set forth hereinafter in connection with the accompanying drawing, wherein- FIGURE 1 is a diagrammatic view of a loom having the invention applied thereto,

FIGURE 2 is a diagram of the electric fields used in the invention,

FIGURE 3 is similar to a part of FIGURE 1 but with the pair of coils and coil between them in a different position, and

FIGURE 4 is similar to FIGURE 2 but corresponds to the coil arrangement shown in FIGURE 3.

Referring more particularly to FIGURE 1, which shows diagrammatically parts of the loom to which the invention more particularly relates, the loom sides and 11 support a breast beam 12, behind which is the lay 13 driven in the usual manner, to reciprocate backwardly and forwardly between front and back centers, passing through top and bottom centers, all as usual in ice loom operation. At one end of the lay are two shuttle boxes 15 and 16 mounted on a box lifter rod 17 and at the other end are shuttle boxes 18 and 19 on box lifter rod 20. It is not essential that moving shuttle boxes be used in order to derive the benefits of the invention. As shown herein a shuttle S is indicated as being in flight along the lay 13 from the left-hand side toward the righthand side of the loom. Due to the fact that the shuttle moves back and forth with the lay and ordinarily travels in front of a reed 21, the shuttle must clear the warp shed and arrive at its destination at one or the other of the shuttle boxes before the advancing lay can push it against warp threads and break them out. Only one shuttle is shown but the shuttle boxes indicate that the invention is not thus limited.

The present invention provides two coils 30 and 31, FIGURE 1, which are embedded in the lay to be passed over successively by the shuttle. Between the two coils is a third coil 32 in which an impulse can be generated and this impulse is used to control the loom. As shown in FIGURE 2, the coils 30 and 31 have magnetic fields indicated by the lines of force 35 which are so related to each other as to be in opposition. A generator 36 serving as a source of alternating current causes electric current to flow through the two coils. In one condition these will be south poles facing the coil 32 and in another condition the poles will be north. The result of this condition is that the electric or magnetic condition of coil 32 is neutral or nil under normal conditions.

As shown in FIGURE 1, wires 40 and 41 connect coil 32 to an amplifier M which acts to increase any impulse received from the coil 32. Wires 42 and 43 then lead the output of the amplifier to the pulse correlator P. The output of pulse correlator P is led by wires 44 and 45 to relay R, shown in the lower right-hand part of FIG- URE l which may be the same as FIGURE 2 of the aforesaid patent.

The loom will be driven by a motor E connected to a motor controller MC as shown in the patent and in FIGURE 1. The loom operates with a switch TS which opens and closes at regular intervals and a second switch D8 which is controlled when the relay R is energized.

It is to be understood that the rotator 62 having the cam 63 rotates once for each beat of the loom or flight of a shuttle and lifts switch TS away from contact 60 at the time in the loom cycle when the shuttle should be giving an impulse for continued operation through coil 32. In FIGURE 1, the switch TS is shown as being open and the motor control MC would stop the loom except for closure of switch DS.

Through most of the cycle of the loom a circuit will be complete from MC through wire 64, switch TS, contact 60 and wire 65 back to MC. When switch TS is open and the loom is running properly current will be flowing from MC through wire 64, wire 68, contact 67, switch DS, wire 69 and back to MC through wire 65. If this latter circuit should be opened at the same time as switch TS is opened no signal for continued running will be given to the motor control MC, and the motor will be stopped.

It is to be understood that the bottom side of the shuttle will have a metallic plate 48, but the shuttle can be principally of metal, if desired. When the opposing magnetic fields of coils 30 and 31 are equal there is then no impulse generated in coil 32 and the relay R will not I plate 48 conducts electric current and also acts as an inductor to cut lines of force. Under these conditions an impulse is generated in coil 32 and relay R will be energized.

FIGURES 3 and 4 show a variation of the coil relationship with respect to the lay and the path of the shuttle. As shown in FIGURE 3, the three coils 75, 77 and 76 are arranged vertically in a direction approximately at right angles to the path of travel of the shuttle. Coils 75 and 76 have the same function as coils 30 and 31, and coil 77 operates the same as coil 32. The generator 36 is connected to coils 75 and 76 and energizes them with equal opposed magnetic fields, so that normally the coil 77 is not excited and therefore remains idle in the circuit. When the shuttle passes along the lay the magnetic field of the upper coil 75 is disturbed more than the field of the remote coil 76 and this sets up a condition, as already explained, which excites coil 77 sufficiently to generate an electric impulse therein which for reasons given in connection with FIGURE 1 will be suificient to effect energization of relay R.

FIGURE 4 is somewhat similar to FIGURE 2 except that it shows coils 75 and 76 vertically arranged with the field of coil 75 over that of coil 76. As is the case in the FIGURE 2, the fields of these coils overlap or reach across the intermediate or central detector coil 77. The operation of the form of the invention shown in FIGURES 3 and 4 is essentially the same as that already described in connection with FIGURES 1 and 2, except that coil 75 is near the path of flight of the shuttle while coil 76 is at a distance below the path and its field is therefore not disturbed as much as the field of coil 75.

From the foregoing it is seen that the electrical conducting body on the shuttle need not be magnetic or ferrous, it being sufiicient if the body can conduct electricity and serve as an inductor which when cutting across lines of force will have generated therein an electric current which has an effect on the field and upsets the balance of fields which had previously existed before the shuttle arrived at the coil. The shuttle can, if desired, be made of a light metal, in which case the plate 48 at the bottom would not be used, and the shuttle while giving indication of arrival at the coils will proceed with substantially no reduction in speed caused by the coils.

I claim:

1. In protection means for a loom operating with a shuttle and dependent for continued running upon enerigization of an electric relay controlled by an electric impulse, two spaced electric coils, a detector coil between said coils, means to energize said two coils simultaneously to produce opposed magnetic fields both of which extend at least part way across said detector coil and at least one of which is in the path of travel of the shut-tle, electric conducting material on the shuttle placed to pass through at least one of said fields to produce a change in said one field which results in producing an electric impulse in said detector coil due to unbalancing the opposed fields by passage of said material through said field, the impulse effective when amplified to cause energization of said relay.

2. In protection means for a loom operating with shuttle boxes and a shuttle and dependent for continued running upon energization of an electric relay caused by an electric impulse, two spaced electric coils arranged along the path of travel of the shuttle between said shuttle boxes, a detector coil between said coils inactive and idle when said coils are in equal electric opposed magnetic field condition, a source of electric power simultaneously creating equal but opposed electric field conditions in said spaced coils, and a metallic body on the shuttle effective when the shuttle moves along said path tocha'nge the electric field condition of at least one of said coils, said change causing an electric impulse to be produced in said detector coil and said impulse causing energization of said relay.

3. The protection means set forth in claim 1 wherein said shuttle is made of electric conducting material.

4. The protection means set forth in claim 1 wherein said electric conducting material on the shuttle is nonmagnetic.

5. The protector means set forth in claim 1 wherein said spaced coils are arranged in a line transverse of the path of travel of the shuttle so that one of them is nearer the path than is the other.

6. The protector means set forth in claim 1 wherein said coils are arranged in a line substantially at right angles to the path of flight of the shuttle with one of said two coils nearer said path than is the other of said two coils.

7. In protection means for a loom operating with a shuttle and dependent for continued operation upon energization of an electro-magnetic relay, a body of electric current conducting material on the shuttle, three aligned electric coils, the central one of which is a detector coil and the other two coils being on opposite sides of said central coil, means simultaneously causing said other two coils to have opposed magnetic fields which reach at least part way across said central coil and normally maintain the latter in a non-excited condition, said body on the shuttle passing through the magnetic field of at least one of said two coils when the shuttle is in flight and thereby changing the magnetic fields across said central coil to induce an impulse therein which is effective to cause ene-rgization of said relay.

8. In protection means for a loom having control means for the operation of the loom dependent upon receiving an electric impulse, two electric devices simultaneously creating opposed magnetic fields, a detector coil between said devices normally inactive electrically due to the fact that the parts of the fields of said two devices which do not negate each other induce opposed currents in said detector coil, and electric conducting means acting due to passage of a shuttle near one of said fields to have induced therein a current which opposes the field it is in and thereby changes the condition of said detecting coil enabling it to deliver an impulse to said control means effective to control the operation of the loom.

References Cited UNITED STATES PATENTS 2,567,751 9/1951 Wolke 139341 2,728,884 12/1955 Pestarini 139-134 X 2,781,794 2/1957 Borderwieck et al. 13934l 2,981,296 4/1961 Paul et al. 139341 3,181,573 5/1965 Stutz 139-341 FOREIGN PATENTS 374,741 6/ 1932 Great Britain.

MERVIN STEIN, Primary Examiner.

I. KEE CHI, Examiner. 

1. IN PROTECTION MEANS FOR A LOOM OPERATING WITH A SHUTTLE AND DEPENDENT FOR CONTINUED RUNNING UPON ENERGIZATION OF AN ELECTRIC RELAY CONTROLLED BY AN ELECTRIC IMPULSE, TWO SPACED ELECTRIC COILS, A DETECTOR COIL BETWEEN SAID COILS, MEANS TO ENERGIZE SAID TWO COILS SIMULTANEOUSLY TO PRODUCE OPPOSED MAGNETIC FIELDS BOTH OF WHICH EXTEND AT LEAST PART WAY ACROSS SAID DETECTOR COIL AND AT LEAST ONE OF WHICH IS IN THE PATH OF TRAVEL OF THE SHUTTLE, ELECTRIC CONDUCTING MATERIAL ON THE SHUTTLE PLACED TO PASS THROUGH AT LEAST ONE OF SAID FIELDS TO PRODUCE A CHANGE IN SAID ONE FIELD WHICH RESULTS IN PRODUCING AN ELECTRIC IMPULSE IN SAID DETECTOR COIL DUE TO UNBALANCING THE OPPOSED FIELDS BY PASSAGE OF SAID MATERIAL THROUGH SAID FIELD, THE IMPULSE EFFECTIVE WHEN AMPLIFIED TO CAUSE ENERGIZATION OF SAID RELAY. 